Incomplete documents of property which has been registered at Pune.

I purchased a property in Pune in 2004 with an agreement with the seller. I made the deed of apartment. However at that time I did not realise the chain of documents are not clear. The chain of documents are not available. However the deed of apartment was approved by the bank for the previous seller and my loan was also passed similarly in Union Bank. I prepaid the loan in 2006 and got the original documents. I made an agreement to sale with a buyer in January 2024. I had informed him about all the documents I possessed. He made an agreement for sale for 40 lakh. He requested me for the chain of documents which I did not have. He however made a deed of apartment with the registration office on 8/2/2024 in Haveli Registration office Pune and we registered the document. The total amount we agreed was 40lakh. He paid me 30 lakh only and told me the rest he will give after his home loan is approved. But for that the chain documents are needed which probably don’t exist. So we are at a stalemate. Can we cancel the deal as I am unable to come up with the documents and he is not paying the balance money. Please advice.